1. Field of Invention
The present invention relates to coating, and more particularly to a method of three dimensional surface coating which is capable of substantially overcoming a conventional difficulty of ineffective coating on surfaces having uniform or complicated surface roundness and/or acute corners.
2. Description of Related Arts
Various methods of coating or painting have been developed to enhance the appearance of particular work pieces so that the work pieces having a fancy or relevant decoration painted or coated thereon will have enhanced marketability or advertising capability.
One of the simplest and conventional methods for painting a metal or plastic article generally comprises the steps of dipping said article in a mixture of varnish and silicone rubber so as to form a protective film on the surface thereof; and bake varnishing the article at a predetermined temperature range. The resulting article is usually coated with a predetermined monochromatic paint.
Yet another simplest conventional method of painting onto a surface for industrial purpose is to utilize a cylindrically shaped paint applicator, which is essentially a roller. The roller is first dipped into a supply of paint, with some of the paint being absorbed in the roller, and then the roller is carried on to the surface so that the paint can be applied thereto. Various powered painting systems have been developed wherein the paint is delivered under a powered system to the paint applicator. The paint applicator is then driven to paint the work piece in question. For some sophisticated systems, a plurality of paint applicators and computer programs or some other sorts of information technology are implemented to assist the painting method so that the system is capable of painting complex and aesthetically sophisticated graphics.
There exist some discrepancies among the above-mentioned conventional methods for painting. Specifically, one major problem is one which involves paint non-uniformity on the surface of the relevant work pieces. This phenomenon is not particularly pressing in work pieces having a fairly large working surface which is to be painted, but the situation will be severely deteriorated when the work piece itself is of complicated external shape, such as a highly complex robot model, in which both rounded and acute corners are plentiful. As a result, for such kind of work pieces, conventional painting methods are of little practical value in that the ultimate quality of painting may be unsatisfactory, if not poor.
In addition, such painting method cannot be utilized under certain conditions. For example, when the work piece is made of metal, the paint cannot be substantially coated on the surface of the metal. In other words, the paint layer will be eventually peeled off from the metal made work piece. Therefore, the painting method is limited by the material of the work piece.
With the advance of information technology, as mentioned earlier, sophisticated systems have existed to deal with some more complicated work pieces. More specifically, computerized probing and painting equipments may be utilized so that painting takes place in a piece meal manner on the surface of the relevant work piece in accordance with a predetermined painting pattern created through a computer program. As such, complicated painting patterns can be created. Moreover, ultra-mini painting equipments have been developed to deal with the acute corners on the work piece. The scenario may sound good, but it is worth pointing out that advanced technology means higher cost and more expensive equipments. This increase in manufacturing costs inevitably leads to increase in selling price, usually severely. This increase in selling price may not cause any problem in that for some high-end product, the cost for manufacturing the product itself may well go above the cost for painting. Yet for some low-end products, the relative cost of painting to manufacturing may be unreasonably high.
Moreover, even though multiple painting layers are overlappedly coated on the work piece, such painting method cannot provide a three-dimensional decoration for the work piece. In other words, the multiple painting layers can only enhance the durability of the coating.
It may be arguable, that other methods of enriching the appearance of the work piece exist, such as chemical coating. However, it should bear in mind that other method involves some other disadvantages. Some are even worse than that of the above-mentioned conventional painting method!